The present invention relates to a copying apparatus with a color copy function. Specifically, the present invention relates to a copying apparatus which performs image adjustment for keeping the quality of color images.
Conventionally, in copying apparatus with a color copy function, images in respective colors of cyan (C), magenta (M), yellow (Y), and black (K) are formed and the images in the respective colors are superimposed to form a color image. Thus, a color image is formed by superimposing a plurality of images, so that copying apparatus perform image adjustment so as to prevent the positions and densities of the respective images from being deviated from each other. As the image adjustment, for example, a resist pattern as an image pattern for image adjustment is prepared for each color, deviation amounts (adjustment values) between a reference color resist pattern and resist patterns in colors to be examined are acquired, and based on the adjustment values, position deviations of the images are corrected.
For acquiring the above-mentioned adjustment values, resist patterns must be formed, so that printing is restricted during the adjustment value acquiring operation. Therefore, there is a known problem that if the adjustment value acquiring operation is performed when executing copy processing, printing is suspended during the adjustment value acquiring operation, and the processing time is extended. Therefore, for example, it is known that the adjustment value acquiring operation is interrupted halfway to shorten the processing time.